OldSynths

> Can anyone explain bipolar CV?

Bipolar CVs are used in most modular systems. But it maybe that the
module in question does not respond to negative (-ve) inputs. Most VCAs
tend to work only with +ve input voltages. However, a negative input
voltage is also a good thing if your VCA has a gain bias (or initial
gain) control. Turn this pot up to half way, and your bipolar input CV
will now open and close the VCA.

A VCF and VCO will happily run with both -ve and +ve inputs. -ve inputs
will control the module's parameter downwards, and +ve ones upwards. So
a VCF's cut-off frequency will move downwards with increasing -ve CV.
But you will of course have to have set the VCF's cut-off to a point
where it can move downwards. If its already at its minimum, it probably
can't go any lower.

But I am puzzled by the fact that your unit had four outputs. Normally
one would expect just two outputs, X and Y. Both outputs would usually
be allowed to go either +ve or -ve.

Regards,

Tony Allgood                       Penrith, Cumbria, England

Oakley Sound Systems                   www.oakleysound.co.uk
Modular Synthesisers      www.oakleysound.co.uk/projects.htm